Flood advisory issued for portion of Big Island; Waipiʻo Valley Access Road, portion of Highway 270 closed

This story was update at 5:13 p.m. Dec. 17.

The approaching Kona low storm system is prompting closures and advisories for the Big Island and statewide.

A flood advisory has been issued until 7:45 p.m. today for areas in the north and northwest portions of the Big Island. According to the National Weather Service, radar indicated heavy rain over portions of North Kona, North and South Kohala and Hāmākua at 4:46 p.m. Rain was falling at a rate of 1 to 2 inches per hour.

Some locations that will experience flooding include Kailua-Kona, Waikōloa Village, Kapaʻau, Honokaʻa, Puʻuanahulu, Puakō, Waimea, Kawaihae, Kohala Ranch, Pōhakuloa Training Area, Waipiʻo Valley, Waimanu Valley, Kukuihaele, Pololū Valley, Kalaoa, Holualoa, Halaula, Honalo, Hawi and Kahaluʻu-Keauhou.

People are advised to stay away from streams, drainage ditches and low-lying areas prone to flooding.

According to Hawaiʻi County Civil Defense, the Hawaiʻi Police Department reports Highway 270 near Kawaihae in North Kohala is closed between mile 10 and 11 because of flooding and debris on the roadway.

Heavy rains and flooding conditions are forecast through Monday. Civil Defense advises to be prepared for additional road closures without notice and drive carefully if travel is necessary.

Hawaiʻi County Mayor Mitch Roth’s office said Waipiʻo Valley Access Road was closed at 3 p.m. today as the stormfront rapidly approaches the island. The road will remain closed until further notice. However, residents and those needing to carry out official business can access the roadway as necessary.

A representative from the Hawaiʻi Police Department, Hawaiʻi County Department of Public Works, private security and/or Hawaiʻi County Department of Parks and Recreation will be onsite at any given time to enforce the closure. Signs and other roadway materials will be placed at the top of the road.

Residents along western and northern coastlines of the Big Island are encouraged to prepare for sustained winds of 20 to 40 mph, with gusts up to 60 mph, the mayor’s office said. Heavy rain and thunderstorms are anticipated for the entire island.

The County will continue to update the public if any other closures are necessary because of the storm.

The National Weather Service in Honolulu also issued several watches and warnings for the entire state in anticipation for the severe weather.

A flood watch is in effect for the entire state from this morning through late Monday night as a strong Kona low storm system approaches the islands.

The weather agency says to expect periods of heavy showers and thunderstorms through Monday night. Although individual showers will tend to move quickly, intense rain rates and the potential for training cells will lead to increased potential for flash flooding.

Flood-prone roads and other low-lying areas could be closed because of elevated runoff and overflowing streams. Urban areas might receive more significant flooding and property damage because of rapid runoff.

Keep an eye on the weather and be prepared to take action should flash flood warnings be issued. Civil Defense urges people to not cross fast-flowing water; turn around, don’t drown.

In addition, a high wind warning is in effect for the entire state through 6 p.m. Monday. In addition, a high wind warning was also issued through 6 a.m. Wednesday for Big Island summits.

Southwest winds of 20 to 40 mph with gusts up to 60 mph are forecast tonight through Monday, especially over and downwind of terrain. Additionally, all areas will be susceptible to strong winds within heavy showers.

Damaging winds could blow down trees and power lines. Widespread power outages are possible, and travel could be difficult.

The strong winds associated with the approaching storm could lead to property damage. Hazardous driving conditions because of powerful cross winds will pose a serious risk
for drivers, especially for lightweight and high-profile vehicles. Loose outdoor items should be brought inside or secured properly.

Civil Defense urges people to be alert for downed utility lines; do not drive over or attempt to move utility lines as they could be energized. Also, treat intersections with inoperable or downed traffic signals as four-way stops.

A winter storm warning is also now in effect for Big Island summits through 6 a.m. Tuesday. Blizzard conditions are expected.

Light snow accumulations are expected tonight and will be followed by periods of heavy snow developing Monday. Total snow accumulations of up to 14 inches are forecasts. Wind gusts as high as 135 mph will also cause significant blowing and drifting of snow.

Travel will quickly become impossible. Blowing snow will significantly reduce visibility, with periods of zero visibility expected. Any travel plans to the summits should be postponed until the threat diminishes.